It is well recognized that many aspects of manufacturing, as well as life itself, is dependant upon water. Water may be characterized by the amount of cations and anions, metals, turbidity, dissolved solids, and so forth, all of which combine to form unique water chemistries. Technology provides the ability to adjust, reduce, or remove such qualities to effectively prepare water for use in a particular application. Proper water treatment systems provide an economical way of conditioning water to a predetermined quality level as required for the particular application. Protection of water supplies from system or equipment failure as well as inadvertent or deliberate contamination are important concerns. While devices and methods exist to analyze water for contaminants, widespread deployment of such devices is expensive and difficult.
Many processes and applications require the use of water having sufficiently low or absent levels of contaminants or harmful substances, and thus rely on the use of water treatment systems to ensure adequate levels of water purity, quality, and/or safety. These water treatment systems may generally use techniques, such as advanced separation, filtration, reverse osmosis, and/or ion exchange processes, as well as the introduction of materials or disinfectants to achieve the desired water quality. However, equipment failure or tampering of these systems may result in poor or unsafe water quality for a given application. Therefore, it is critical that any water treatment system used to purify or treat water for any such applications is adequately monitored to ensure that the desired levels of water purity, quality, and/or safety are met. One application in which water quality is important is in providing potable drinking water to the public. Most water treatment systems for the production and distribution of drinking water to the public rely, for example, on the introduction and maintenance of materials, such as disinfectants, into the water system to protect against biological or chemical contamination. Chlorine, in the form of gas or hypochlorite or hypochlorous acid, is one of the most common materials used for this purpose. Substitutes such as chloramines, ozone, hydrogen peroxide, peracetic acid, chlorine dioxide, and various mixed oxides are also used. Many of these materials have a more or less common mode of action. They rely on some sort of oxidation to effect the deactivation of biological organisms and the destruction of other organic compounds present in the water to be treated. The reaction rates of the various materials, such as disinfectant compounds, are reasonably well known and well characterized. However, excessive amounts of these materials may cause problems on their own. Thus, it is important that adequate monitoring is performed to ensure that sufficient but not excessive amounts of these materials or disinfectants are maintained in a water treatment system.
Municipal drinking water may be obtained from a variety of sources, which can be made potable by use of proper water treatment equipment. For example, a reverse osmosis system may be used to lower the total dissolved solids from sea water with minimal pretreatment to produce potable drinking water. Despite the sophistication of pretreatment of seawater, improper monitoring or operation can allow the seawater to quickly foul membranes. If fouling occurs, but is found quickly, the membranes may be cleaned, and water contamination and associated water treatment repairs may be averted. However, if the fouling is not detected quickly through proper monitoring, the membranes can be irreparably damaged, and expensive partial or total membrane replacement would be required. The cost of unplanned membrane replacement, not including the lost revenues typically associated with down time, can make such a system cost prohibitive.
Another application in which water quality is important is with Waste Water Treatment Plants (WWTP). The treatment and subsequent recycling of wastewater is a cornerstone of the quality of life in the industrialized world. Cities, industries, and agricultural operations produce large quantities of wastewater, all of which must be treated to some degree to remove contaminants or pollutants before the water is suitable for recycling or discharge into the environment, such as streams, rivers or oceans. In metropolitan areas, central waste water treatment plants must treat water from a variety of sources including city, industrial, and agricultural waste water. In many cases, generators of industrial waste water are required to install and operate waste water treatment plants at their own sites before discharge into central water collection systems. At the central water collection system, industrial wastes may generally be mixed with domestic or city waste water and other untreated waste sources. These mixed wastes are then transported to the central waste water plant or sewage treatment facility for final treatment before discharge.
Increasingly, the need for pure water is causing more and more municipalities to install waste water recovery processes to recycle municipal WWTP effluents back into water of suitable quality to be used for potable drinking water or irrigation. For example, such recovery processes may recover secondary treated municipal effluents using reverse osmosis, which may then be injected back into an aquifer. More and more of these installations are planned throughout the United States and the rest of the world.
One difficult aspect of treating municipal waste water effluent is that neither the flow rates nor the mix of contaminants are constant. This is particularly true for a municipal WWTP with collection systems that include a variety of industrial discharge sources in addition to the usual sanitary discharges from homes, businesses, schools, and so on. While the sanitary discharges are well characterized in terms of composition and treatability, the addition of industrial wastes means that the WWTP must plan for a wide variety of contaminants. In general, most WWTP systems cannot deal effectively with every situation. Even with excellent design and engineering, the large fluctuation in the type and quantity of contaminants reaching the WWTP often result in varying levels of effective treatment in the discharge from the WWTP. For a tertiary water recovery plant treating the effluent from the WWTP this can be particularly difficult since many contaminants are not readily removed even by processes such as reverse osmosis. In addition, certain contaminants can also foul reverse osmosis, ultrafiltration, and microfiltration membranes, causing loss of performance or membrane damage. Therefore, it is important that WWTPs are monitored to ensure that contaminants are properly removed before discharge or reuse back into the environment and to avoid damage to expensive equipment.
Although systems exist for the local monitoring of discrete, independent treatment site locations for individual analysis, these systems do not contemplate remote monitoring of one or a number of water treatments sites throughout a collection system that simultaneously feed effluents into a central water collection system of a WWTP. There remains a need for a system designed for remote monitoring of a WWTP which may collect and interpret data from one or a multiple number of remote industrial or water treatment sites viewed and analyzed as an aggregate water treatment system.
Water is also required for steam generation in nuclear reactors. The boilers of these nuclear reactors operate at extremely high temperatures which requires a very high quality of water. It is critical that the process system is monitored properly to avoid expensive boiler cleanings and the associated down time. Such systems may also include the need to monitor hazardous boiler chemicals, such as hydrazine, requiring highly qualified personnel. These examples highlight the importance of monitoring the operation of water treatment systems to not only ensure sufficient water quality, but also to avert costly equipment repair or replacement.
Water quality is also important for many manufacturing processes. For example, the manufacturing of semiconductors requires an ultra-pure water quality. Again, it is critical that the water treatment system is monitored properly to avoid latent defects in the manufacturing of products, such as semiconductors.
As yet another example, monitoring water quality is also important to avoid or lessen the consequences of equipment failure or deliberate tampering, such as by terrorist act, in contaminating the water supply. Adequate monitoring may help to catch any such contamination of the water supply to avoid harm and ensure that appropriate action is taken.
One of the problems with maintaining advanced processing equipment is the need for highly qualified individuals to monitor its operation. Employment of a full time staff is costly and can be problematic since such monitoring is repetitive, and highly qualified individuals can easily become bored. For this reason, advanced separation processes may include a large assortment of strategically placed sensors that are typically incorporated into a computer system capable of comparing the sensor values against a pre-set quality level. However, if the operator does not recognize a particular alarm condition, the elaborate array of monitoring equipment is effectively useless.